STOP Early Journal Content on JSTOR, Free to Anyone in the World This article is one of nearly 500,000 scholarly works digitized and made freely available to everyone in the world by JSTOR. Known as the Early Journal Content, this set of works include research articles, news, letters, and other writings published in more than 200 of the oldest leading academic journals. The works date from the mid-seventeenth to the early twentieth centuries. We encourage people to read and share the Early Journal Content openly and to tell others that this resource exists. People may post this content online or redistribute in any way for non-commercial purposes. Read more about Early Journal Content at http://about.jstor.org/participate-jstor/individuals/early- journal-content . JSTOR is a digital library of academic journals, books, and primary source objects. JSTOR helps people discover, use, and build upon a wide range of content through a powerful research and teaching platform, and preserves this content for future generations. JSTOR is part of ITHAKA, a not-for-profit organization that also includes Ithaka S+R and Portico. For more information about JSTOR, please contact email@example.com. 542 BOTANICAL GAZETTE [December Lichen growth. — As the results of experiments and observations extending over a period of 8 years, Fink^ has determined the rate of growth in certain crustose and foliose lichens, as determined by measurements of the diameter of the thallus, to vary from increases of o . 36 cm. per year for Umbilicaria pus- tulata, and 0.42 cm. for Physica pulverulenta, to 1 .3 cm. per year for Parmelia Borreri and P. caper ata, and 1.75 cm. for Peltigera canina. Some of the inter- mediate annual increments were 0.2-0.75 cm. for Graphis scripta, 0.6 cm. for Verrucaria muralis, and 1 . 16 cm. for Parmelia conspersa. In these measure- ments Fine has given us practically the only definite data we possess relative to the increase in size of these pioneer plants. With regard to migration, Fink declines to indulge in speculations regarding possible methods, and says " nothing is definitely known further than seeing parts of Cladonia thalli lying on some of the quadrats in early stages of ecesis." — Geo. D. Fuller. Vegetation studies in Natal. — Bews continues his interesting studies of the vegetation of Natal, 14 his latest paper dealing with the ecology of the Drakensberg. 15 These mountains exhibit picturesque and even stupendous scenery, the highest peaks being more than 11,000 ft. above the sea. The most extensive formation, as elsewhere in Natal, is the veld or grassland. The alpine veld is composed more of tussock grasses than is the lowland veld, and the growth forms are more xerophytic. An interesting formation is the Protea veld, dominated by various species of small trees of the genus Protea. The climax formation is the bush, dominated by species of Podocarpus, and occupy- ing the more protected situations. The mountain top vegetation is markedly xerophytic, and is dominated by composites (as Eelichrysum) and heathers (as Erica). The last section of the paper deals with successions and inter- relations. — H. C. Cowles. Tree growth in Iowa. — In presenting data upon tree growth in the vicinity of Grinnell, Iowa, Conard 16 brings out several interesting facts in addition to the average annual increment of several species. There seems to be conclusive evidence that trees are encroaching upon the grasslands, and this is ascribed to the elimination of prairie fires during the past half century. While this accounts for the present increase of forested areas, it is not regarded as explain- ing the presence of grasslands which constituted the natural vegetation upon the best soils in the region. These richer soils are very favorable to tree growth and the increments are sufficiently large to indicate that timber would « Fink, Bruce, The rate of growth and ecesis in lichens. Mycologia 9:138-158. IQI7- i4 Bot. Gaz. 64:85-86. 19 1 7. « Bews, J. W., The plant ecology of the Drakensberg Range. Annals Natal Museum 3:5 II_ S65- pis. 4- figs- 3- : 9i7- 16 Conard, H. S., Tree growth in the vicinity of Grinnell, Iowa. Jour. Forestry 16:100-106. 1918.